Poststack seismic
data contain a tremendous amount of information about reservoir stratigraphy,
sedimentology, and physical properties. However, this information is far
from fully utilized because of (1) the lack of understanding of the relationship
between geology and its seismic responses and (2) poorly conditioned seismic
data that fail to express the geology in a way geologists can understand.
Geology-guided reconditioning of seismic data is the key to improve extraction
of relevant geologic information. At Fullerton field, the most convenient
and useful tools for data reconditioning are phase shifting and high-frequency
enhancement. A simple seismic phase rotation (to 90º) reconditions
seismic data for impedance representation, roughly linking seismic amplitude
directly to log lithology and porosity. High-frequency enhancement raises
the dominant frequency of 3-D seismic data from 30 to 50 Hz, significantly
improving seismic resolution. More accurate and finer scale seismic mapping
of reservoir parameters is achieved from progressive inversion that seamlessly
integrates the geologic interpretation of well-seismic data and model-based
seismic inversion for high-resolution (20 ft) impedance models.